JPS60206545A - Manufacture of pillar material - Google Patents

Abstract

PURPOSE:To manufacture a pillar material that constitutes a junctional part to which a beam can be welded easily by making a centrifugal cast tube which is a thick large diameter part an end side of linear tube part of which is bulged out to outside a material tube, and reducing the thick large diameter part by drawing and forming to a pillar material. CONSTITUTION:A material tube 10 having a thick large diameter part 12 bulged out to outside through a tapered part 13 on an end of a linear tube part 11 having the same inner diameter with the thick large diameter part is made by centrifugal casting. The thick large diameter part 12 and tapered part 13 of the centrifugal cast tube 10 is drawn by a press etc. to reduce the thick large diameter part 12 and tapered part 13, and inner face is bulged out to inside. At the same time, outer face is formed to a flat plane 22, and a pillar material 20 having a tapered part 23 between the linear tube part 11 and the plane 22. By welding the flat plane 22 sides of the pillar material 20, a joint part to which a beam can be welded easily can be constituted.

Description

[Detailed description of the invention] The present invention relates to a method of manufacturing column materials for steel structures and the like.

Beam joints (joint parts) of cylindrical columns in steel structures are formed to be thick or provided with annular protrusions in order to ensure required joint rigidity. Figure 8 shows circular pipes (45, 45)
and a thick-walled circular pipe (46) that will become the joint part are joined by butt welding of the pipe end faces to form an assembled column, and the thick-walled circular pipe (46)
This is an example in which a beam (42) is welded to the outer surface of a circular pipe (46), and FIG.
8) Weld them together to form an assembled column, and its annular protrusion (4
7, 47) and the flange (42・l, 42・) of the beam (42).
This is an example in which welding is performed by applying 1).

The pillar shown in Fig. 8 above is assembled using drawn steel pipes, welded steel pipes, etc. as the circular pipes (45) and (46), but the thick-walled circular pipe (46) forming the joint part and the circular pipes on both sides thereof ( 45,45)
Since the wall thickness of the welded joint (W) changes rapidly at the welded joint (W), there is a drawback that stress concentration and a decrease in proof strength due to local deformation are likely to occur during use.

Furthermore, it is undesirable that there are two weld lines in a portion that causes stress concentration.

On the other hand, a centrifugally cast tube is used as the circular tube (48) used to assemble the column having the annular projections (4-7, 47). Figure 10 shows the casting method. (1) is a mold, and a large diameter portion (7) is provided on one end side of the inner surface of the mold. (8) is a liner fitted into the large diameter part (7), and the step wall surface (81) of the liner (8) and the large diameter part (7)
) and the step wall surface (71) define an annular groove (9) that goes around the inner peripheral surface of the mold. Note that (5, 5) are hot water stopper bands (end plates) fitted to the openings at both ends of the mold.

When molten steel is poured into the mold (1) while rotating about its center line, an annular protrusion (47) is formed in an annular groove (9) under the action of centrifugal force as shown in the figure. The circular tube (48) with

The centrifugal force casting method is suitable for mass production, and can manufacture circular tubes (column materials) as assembled column constituent units at low cost. Furthermore, since the column assembled using the circular tube as a constituent unit has only one weld line (W) at the joint, it is advantageous in terms of strength compared to the column shown in FIG. 8.

However, in the centrifugal casting according to the above-mentioned casting method, the assembly of the mold for forming the annular groove (9) requires a lot of time and effort, and the productivity is extremely low.
8) and the step wall surface (81) of the large diameter part of the mold (7), (7)
1) Deformation and cracking are likely to occur due to thermal stress during casting, resulting in a short service life. Moreover, the annular protrusion (47
, 47), the spacing of the protrusions, the protrusion height, etc., change each time depending on the design of the column, so it is not possible to start manufacturing the mold or liner until the drawings are finalized. There are drawbacks such as significant difficulty in meeting delivery dates.

In addition, since the joint part of the conventional column has a shape that bulges outward from the surfaces of the straight pipe parts above and below, the entire bulging surface of the joint part is covered with the beam (42). Regardless of the case, if the beams are joined only partially, for example in two or three directions, the bulging surfaces other than the joined parts of the beams will remain exposed and can be seen directly. You can't escape the unsightly appearance.

Furthermore, since the joint part of a conventional column has a circular external cross-sectional shape, when joining the beam by welding, an arc-shaped groove is formed on the end face of the beam so as to match the convex circumferential surface of the joint part. must be formed. Welding and assembling the beam to the joint portion of the convex peripheral surface is extremely troublesome work, and the productivity is also very low.

The present invention solves the above-mentioned problem regarding the cylindrical column, and as shown in FIG. Provided is a method for manufacturing a column material in which a thick-walled reduced diameter portion (21) having a flat surface (22) included inside an extended circumferential surface of a tube portion is formed via a tapered portion (25).

The method for manufacturing the column material of the present invention is to use a centrifugally cast pipe having a thick walled large diameter portion that bulges outward at one end of the straight pipe portion as a blank pipe, and to draw the thick walled large diameter portion. A column material having the above shape is obtained by reducing the diameter.

The present invention will be explained in detail below.

As shown in FIG. 2, the centrifugally cast pipe used as the raw pipe in the present invention has a thickness that bulges outward through a tapered part (13) at one end side of a straight pipe part (11). Meat large diameter part (
12). The straight pipe part (11) and the thick large diameter part (1
2) have the same inner diameter, and the tapered portion (13) is defined by an inner circumferential surface (14) and an outer circumferential tapered surface (15) that is a conical surface.

The centrifugal casting tube (10) is cast according to the casting method shown in FIG. (1) is a centrifugal casting mold, (2) is a straight pipe forming part in the mold, (3) is a large diameter part, and (4) is a tapered surface. End plates (5, 5) are fitted into the openings at both ends of the mold (1), and the pouring hole (6) of the end plate (5) is rotated about the central axis of the mold. A predetermined amount of molten steel is poured into a mold, and by the action of centrifugal force, a cylinder (10') of molten metal with a predetermined layer thickness is formed along the inner wall of the mold and solidified, resulting in a shape as shown in Figure 2. A cast tube is obtained.

Next, the centrifugally cast tube (10) is used as a blank tube, and its thick large diameter portion (12) and tapered portion (13) are subjected to drawing processing using a press, a roll, or the like. The drawing process of the raw pipe (10) may be performed in the as-cast state after being pulled out from the mold, or may be performed in the state where it has been subjected to subsequent heat treatment such as normalizing treatment. Through this drawing process, the thick large diameter part (12) and the tapered part (1
3) is reduced in diameter, and as shown in FIG. 1, the inner surface is bulged inward while maintaining the required thickness, and a flat surface (22) is formed on the outer surface. The plane (22) is the straight pipe part (11
) is formed so as to be included inside the extended surface of the circumferential surface. In addition, in the drawing process, in order to avoid a sudden change in the level difference between the outer surfaces of the thick-walled reduced-diameter portion (21) having a flat surface (22) and the straight pipe portion (11), the thick-walled reduced-diameter portion (21) is A tapered surface (23) is formed on the outer surface between the straight pipe portion (11) and the straight pipe portion (11). Note that the inner tapered surface (24) is formed in the process of diameter reduction by drawing. These tapered surfaces (23) and (2
4), a tapered portion (25) is provided between the thick diameter reduced portion (21) and the straight pipe portion (11).

Figure 4 shows an example of a column material obtained by drawing a raw pipe. The thick-walled reduced diameter portion (21) has a substantially rectangular outer shape consisting of four planes (22). Corner between planes (
26) may be a curved surface that curves in the circumferential direction as shown in the figure. The plane (22) of the thick reduced diameter part (21) is the surface to which the beams are joined, and therefore the thick reduced diameter part (21) is an arbitrary plane having a number of planes corresponding to the number of beams to be joined. It is formed into a polygonal shape.

Fig. 5 shows a thick-walled reduced diameter part (
21) is an example of a pillar material having the following. Depending on the joining direction of the beams, two planes (22) may be formed in two directions at right angles. Further, when the number of beams to be connected is one, only a portion of the thick-walled diameter-reduced portion may be formed into a flat surface, and the other portion may be formed into an arcuate surface. In addition, the curved surface (26) and the circular arc surface (27) at the corner between the two planes in the above example are included inside the extended circumferential surface of the straight pipe part (11), or are almost the same as the extended circumferential surface. Although it is desirable to form them so that they coincide with each other, they may protrude outward from the extended circumferential surface within a range that does not impair the aesthetic appearance in use. In addition, the curved surface of the corner (
26) or when there is a step between the circular arc surface (27) and the inner peripheral surface of the straight pipe portion (11), a tapered surface (28) may be formed.

The necessary number of the above-mentioned pillar materials (20) are prepared, and these are assembled into a unit by welding the end faces on the thick wall reduced diameter part (21) side together and the end faces on the straight pipe part (11) side. It is assembled as. Figure 6 shows a beam (42) attached to the joint part (41) of the assembled column (40) manufactured in this way.
An example of joining is shown below. The beam (42) is joined to each plane (22) of the joint part (41). In addition, there is only one weld line (W) in the joint part (second work).

According to the method of the present invention, a column material as a unit of an assembled column can be obtained by using a centrifugally cast tube as a blank tube and subjecting a part thereof to a simple forming process by drawing. It is cheaper than the method. Moreover, the inner shape of the mold used for centrifugal casting of raw pipes is different from the straight pipe forming part (2
), the large-diameter part (3), and the inclined surface (4) between them, and it has a relatively simple shape, and does not require a complicated casting method as shown in Fig. 10, so mold assembly is easy. There are no problems such as troublesome process or early damage to the mold.

In addition, in a column in which the column material according to the present invention is assembled as a unit, the joint part has a shape smaller in diameter than the outside diameter of the straight pipe part by drawing, and the outer surface of the joint part and the outer surface of the straight pipe part are connected to each other. Since the difference in level between the pillars is very small, the pillars are more aesthetically pleasing when in use compared to conventional pillars that have external joints that bulge outward. Moreover, the joint part has the required wall thickness, and the thickness gradually changes from the thick wall part to the straight pipe part, and there is only one weld line at the joint part, so it is not strong. But it's excellent.

In addition, since the joint part of the beam at the joint part is flat, the end face groove shape of the beam may be linear, and it can be adjusted to the convex curved surface of the joint part, as in the case of joining a beam to a conventional column. There is no need to form an arcuate groove. Therefore, it is easy to insert and assemble beams between columns, and at the same time, welding work is also easy.

Furthermore, the pillar materials manufactured by the present invention can be used not only as pillar materials for buildings, etc., but also as concrete blocks for constructing marine structures (e.g., sea walls, breakwaters, bridges, off-shore breakwaters, mooring facilities for aquaculture). Used as pile material in combination with. In particular, it is useful as a pile material when the continuous pile driving Bronoque method (PBS method), which has been attracting attention recently, is applied.

As shown in Fig. 7, this PBS construction method includes a truncated conical inner wedge (53) and a wedge receiver (52) suspended from a PC @ wire (51) at the bottom of the shaft (20). This is a construction method in which a concrete block (55) is stacked on top of an outer wedge (54) having an inclined inner circumferential surface that matches the outer circumferential surface, and a concrete block (55) is stacked on top of the wedge. A wedge effect gradually works due to its own weight, and when the predetermined concrete block is set and the PC steel wire is tensed, the block and pile become an integral structure. In this case, the point part of resistor (20) is a stress concentration part, so it needs to be thicker than other parts to withstand it, and it is necessary to have multiple parts rather than a cylindrical part. A polygonal shape made of planes can produce a much stronger wedge effect.

From this point of view as well, the column material in which polygonal thick-walled portions are formed according to the present invention is suitable as a coloring material for the PBS construction method.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view schematically showing the shape of the column material after drawing according to the present invention, Fig. 2 is a partially cutaway front view illustrating the raw pipe used in the present invention, and Fig. 3 4 and 5 are perspective views illustrating the column material obtained by the present invention, and FIG. 6 is a unit view of the column material obtained by the present invention. FIG. 7 is a cross-sectional view illustrating another usage of the column material obtained by the present invention, and FIGS. 8 and 9 show the specifications of a conventional column. FIG. 10 is a partially cutaway front view showing the mouth portion, and a sectional view showing a conventional centrifugal casting method for pillar materials. 1: Centrifugal casting mold, 2: Straight pipe forming part, 3: Large diameter part, 10
: Raw pipe (centrifugally cast pipe), 11: Straight pipe part, 12: Thick walled large diameter part, 13: Tapered part, 20: Pillar material of the present invention, 21: Thick walled part, 22: Plane, 25: Tapered part , 40: Assembly column, 41
: Shiguchi part, 42: Beam, W: Welding line. Agent Patent Attorney Arata Miyazaki Department

Claims (1)

[Claims] (1) The inner surface bulges inward at one end of the straight pipe,
A method for manufacturing a column material in which a thick-walled reduced diameter part having a flat surface included inside an extended circumferential surface of a straight pipe part is formed on the outer surface via a tapered part, the tapered part being formed on one end side of the straight pipe part. A centrifugally cast tube with a thick wall and large diameter section that bulges outward through the tube is used as the blank tube, and by drawing the thick wall and large diameter section and the tapered section, the diameter can be reduced while maintaining the required wall thickness. A method for manufacturing a column material, characterized in that the inner surface is bulged inward and a flat surface is formed on the outer surface.